Frequency changer



Dec. 3, 1929. G. A. LOCKE 1,738,253

FREQUENCY CHANGER I Filed Jan. 11, 1924 //7 van/0r: George/flame p my Patented Dec. 3, 1929 UNITED STATES PATENT .orrlca- GEORGE A. LOCKE, O1 GLEN COVE, YORK, ASSIGNOB TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION 01 NEW YORK FREQUENCY CHANGER Application filed .January 11, 1924. Serial No. 885,888.

This invention relates to a frequency changer and more particularly to a relay arrangement for causing a series of impulses of current of alternately different polarity to produce another series of impulses also of alternately different polarity but of lesser frequency.

Relay arrangements are known in which a series of impulses of one polarity are used to produce another series of impulses having one-half the period of the first. Such arrangements depend upon the release of neutral relays due either to the opening of the energizing winding or to the short circuiting thereof. Consequently, such systems are comparatively slow acting, that is, they are effective up to an impulse frequency not materially greater than ten impulses per second.

An object of this invention is to effect frequency reduction of a series of impulses of alternately different polarity by means of relays and at a greater speed than heretofore.

In one embodiment of the invention, four relays are employed each of which is positively actuated. One relay actuated by current from a source of alternating current energizes two other relays, each at one-half the rate at which the first relay is energized. Automatic switching circuits are employed to effect the energization of these two relays in proper sequence. A fourth relay connected in series with one of said two relays controls the output impulses of the system for actuating a suitable electrical device. A vibrating tuning fork may be used in place of the first mentioned relay to'energize said two relays and a phonic wheel may be driven by the output impulses. Polar relays, which are inherently high speed devices. are used.

The novel features which are considered characteristic of this invention are set forth with particularity in the appended claims. The invention both as to its organization and method of operation together with other objects and advantages thereof will be understood from the following description, having reference to the accompanying drawing consisting of two figures.

Fig. 1 illustrates one embodiment of the invention for reducing the speed of operation of an electrical device or a phonic wheel by one half what it would be if directly actuated by a source of alternating current on one hand or by a vibrating tuning fork onthe other.

Fig. 2 shows an arrangement for reducing the speed to one third. 1

Referring now to Fig. 1 of the drawing,

' a source of alternating current 4 is connected relays are similar to relay A, except that the 1 polarizing magneticfield is supplied by a third winding which is energized by current from battery 7. This winding for each relay is shown centrally located between the two energizing windings. In circuit with these polarizing windings is a resistance 8 for fixing the amount of current flowing therein.

The resistance 8 may be adjustable, if desired.

The battery 7 which has a mid-tap dividing it into two sections a and 6, also supplies current to the operating windings of relays B, C and D. Current in the operating wmdings of relays B, C and D flowing from right to left causes the armatures to so move as to close left-hand contacts 9, 11 and 13 respectively. Current flowing in the opposite direction through these windings causes-the closure of contacts 10, 12 and 1 respectively.

The contacts 9 and 10 of relay C are alter nately included in the energizing circuit of relay D, while the contacts 11 and 12 of relay D alternately control'the energizing circuit of relay C. Relays C and D may aptly be called commutating relays since they perform a switching operation which will be described more in detail hereinafter. Resistances 15, 16, 17 and 18 are included in the circuits from battery 7 to determine the current values under various circuit conditions.

The operating winding of relay B is connected in series with that of relay D and therefore the armature of relay B operates in synchronism with that of relay D. The contacts of relay B control the application of positive or negative impulses of current from attery 7 through switch S2 to any suitable electrical device M, such as a frequency meter. Resistances 19 and 20 are included in the battery circuits to determine the values of current under various circuit conditions.

When the switches S1 and S2 are both thrown to the left as shown, the electrical device M is controlled by current from the alternating current source 4.

When switch S1 is thrown to the right, electrical device M is controlled by tuning fork F. The fork F is driven in well known manner by driving magnet 21 which is energized by current from battery 22. The vibration of the fork F alternately closes contacts 23 and 24 which control relays C and D in the same manner in which they are controlled by contacts 5 and 6 of relay A.

When switch S2 as well as switch S1 is thrown to the right, the phonic wheel P is driven by impulses from battery 25 under the control of tuning fork F. The phonic wheel P may be used to driveany suitable apparatus, such as the signal transmitter in a submarine cable telegraph system.

When the switch S1 is thrown to the left and switch S2 to the right, the phonic wheel Pis-driven under the control of the alternat ing current source 4.

Operation The operation of the apparatus of Fig. 1

y will now be described.

' to the same lows:

- Assuming that it is desired to operate the electrical device M from source 4, switches S1- and. S2 will be thrown to the left, as shown,

Energizing current from the source 4 will cause the armature of relay A to vibrate, thereby alternately closing contacts 5 and 6. The effect of the alternate closure of contacts 5 and 6 .upon relays C and D will now be considered step by step through one cycle of operation. Four steps are required to complete a cycle ofoperation starting from one position of all of the relays and returning again position. These steps are as fol- Step a.-Assume that all the relay armatures are in such positions as to close their left may be traced from the positive terminal of section a of battery 7, contact 10 and armature of relay C, energizing winding of relay D, energizing winding of relay B, contact 28 of switch S1, contact 5 and armature'of relay A to the negative terminal of section a. Current will now flow from left to right through relay D and contact 12 will be closed. At the completion of this step, contact 5 of relay A, contact 10 of relay C, contact 12 of relay D and contact 14 of relay B will be closed. I

Step 0.The third impulse of current from source 4 will cause the closure of contact 6 of relay A to again complete an energizing circuit for relay C. This circuit may be traced from the positive terminal of section a of battery 7, contact 12 and armature of relay D. energizingwinding of relay C, contact 26 of switch S1,-contact 6 and armature of relay A to the negative terminal of section a.

Current will flow from right to left through relay C and contact 9 will be closed. At the completion of this step, contact 6 of relay A, contact 9 of relay C, contact 12 of relay D and contact 14 of relay B will be closed.

Step d.-The fourth impulse of current from source 4 will cause the closure of contact 5 of relay A to' again complete an energizing circuit for relay D. Current will flow from right to left through relay D to cause the do sure'of contact 11 and the conditions are the same as at the beginning of Step a. i

The condition of the relays at the completion of each step is readily shown by Table I below where the sloped lines represent the relative position of the contact making portion of the armatures of the several relays.

Table I Relay A Relay D Relay B From the above description and table it will be seen that the armature of relay B vibrates at one half the frequency of the armature of relay A. Therefore, contacts 13 and Relay 0 14 are alternately closed at half the frequency of the alternate closure of contacts 5 and 6. A series of impulses of current of alternately different polarity from sections a and b of battery 7 are therefore impressed upon the electrical device M, and these impulses occur at half the frequency that they would occur if received directly from the source 4.

From the above description it is clear that the electrical device M may also be operated under the control of tunin fork F since contacts 23 and 24 are mere y substituted for contacts 5 and 6. Further detailed description is therefore not required.

Referring now to Fig. 2 an arrangement is there shown for actuating the electrical device M under the control of source 4 at one third the speed it would operate if directly driven by current from the source 4. Similar elements in both the arrangement of Figs. 1 and 2 are indicated by the same reference characters. Y

planation of Table I, it is suflicient to show.

the condition of the several relays of Fig. 2 at the completion of each step by means of Table II below. -The significance of Table II is the same as that of Table I except that a dot above the sloped line is used to indicate quickly to the eye which of the relay armatures chan ed sition durin a 'ven ste g p0 g g1 p ducing a series of im ulses of current of al- Table II Relay desiccation Step AGHIJ- The sco e of the invention is defined by the appen ed claims.

What is claimed is: r

1. In an electrical system a source of alternating current, a source of direct current,

vmeans including relays controlled by alternating current from said source for producing impulses of current from said direct current source of frequency different from, but dependent on, that of said alternating current, and means controlled bysaid impulses of different frequency.

2. In an electrical system, a source of alternatin current, a polar relay actuated by current rom said source, and switching relays havin energizing windings artially controlle by said polar relay and armatures operating at a frequency dlfierent than that of said source.

3. In an electrical system, means for roducing a series of impulses of current 0 alternately dififerent polarity of one periodicity, and a polar relay arrangement actuated by said series of impulses to produce another series of impulses of different periodicity.

4. In an electrical system, means for producing a series of impulses of current alternately different polarity of one periodicity,

and a polar relay arrangement actuated by said series of impulses to produce another series of alternately diiierent polarity of different periodicity.

5. In an electrical system, means for roducing a series of impulses of current 0 a1- ternately difi'erent polarity of one periodicity, and a circuit including a polar relay actuated by said series of impulses to produce another series of impulses of one-half the periodicity of the first series of impulses.

6. In an electrical system, means for proternately different p0 arity of one periodicity, and a polar relay arrangement actuated by said series of impulses to produce another series of impulses of alternately different polarity of one-half the periodicity of the first series of impulses.

7. In an electrical system, a pair of contacts, means to alternately close saidcontacts, two polar relays, each having an energizing winding, an armature and a pair of contacts alternately closed by the actuation of said armature, an energizing circuit for one of said relays including in series one of said first pair of contacts and one of said pair of contacts of the other polar relay, and an energizing circuit for the other of said polar reays including in series the second contact of said first pair of contacts and one of the contacts of said pair of contacts of the first of said two polar relays.

In witness whereof, I hereunto subscribe my name this 27th day of December, A. D.

GEORGE A. LOCKE. 

